Semiconductor relay device



y 22, 1952 L. P. HUNTER SEMICONDUCTOR RELAY DEVICE Filed Feb. 8, 1951Fig.2.

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INVENTOR Lloyd P. Hunter. B

Patented July 22, 1952 PATENT OFFICE S M OND GT R RELA DE IC iLloyd i-P.Hunter, :Pittsburgh, 'Pa., assignor to -Wesfinghquse ElectricCorporation, East Pittshi h Pa a s mm t w s van -App'lication 'Fbruarys, 1951 Serial N0.;209 ,-9 1 8 ;51 Claims. (01.;171-97) relay devices of:the. triggered type, in which there is utilized:aisemi-conductivedeviceh'aving a plurality of-electrodes associated therewith;

It has been conventional :practice for many years to utilizeelectricdischarge-tubes of various types, as the basic element of.electronic :r'elay devices. One of 'the electric .1disoharge :tubescommonly-used in :relay devices o-f the triggered type is the'thyratron.While thyratrons are generally satisfactory for triggered type-relayservice where the power requirements are relatively high, theyaresubj'ect to a number of disadvantages in applications in which relay'apparatus'having extremely low power handling capability can beutilized. Principal among these disadvantages are "comparatively longre-set time (of the order of several microseconds), relative large sizeand complexity, and the requirement for a "filament power supply. 1

Recent developments in the art of semi-conductors have resulted in theintroduction of .a new device, termed a transistor, which is known to becapable of performing some of the functions of a vacuum tube. Thetransistor comprises a body or block ofsem'i-conductive material, whichmay be silicon or germanium, with which are associated three electrodes.Two of these electrodes, called the emitter and collector are rectifyingelectrodes, usually in the 'form of pin-pointed conductive probes,located in' proximity, in contact with the semi-conductive material. Thethird electrode, called the base electrode, is anon-rectifying-electrode locatedelsewhere on the semi-conductive body,usually a plate of conductive material, placed contiguous to thesemiconductive body or the block. The transistor is very small insize,-simple in structure, doesnot-require a filament power supply, andis operable at extremelylowpower levels.

Another object oiimy invention is to provideian improved electronicrelay device which X10188 :iiot require atfilamen'trpower supply; 7 1 1:Another object :of my invention is I to provide an improved electroniorelay. apparatus 'WhiQhliS of very simple, smalLand compact structure. Afurther object of my invention is to provide an :improved electronicrelay device of the triggered type, .;which can be triggered (byeither-1a positive or negative pulsei without *changingi -the polarityof :other circuit parameters. 4.

A further object of my invention-is 513,0 prom e an'improved electronictranslating apparatus o1 the triggered type, which ,:shall iutilize-caasemiconductive device {having three electrodesnand which can bethermally triggered. i

I A further'obiect of myninvention is =to proyid an improved triggeredtype electronic relay '.-de;-' vice which shall have an extremely {shortre-set time. .'i

A still :further object of, my=jinvention--:iSf:to provide :anelectronic relay apparatus utilizing ;-a body 1 or TblOCk of-semi-'conductiv,e :material ,hav; ing threeiielectr'odes and in whichPan; A; C. r8336; potentialcjagn -be:effectivelyused. a

There-is shown-in Fig. 1 lot the-drawing, ;;a" device well (known inthegpriorv art as a photo-peak diode. :FIhisdeviceeomprises a-block of3N type "semi-conductive material, such as gel?- manium, 'm which 'thereis a small "-EP ztypej 1in? clusioni. A collector probe electrode :3:is-pla ced nearthe P-eN boundary, :-inc'ontact with ,the' inclusion r2.A: base-electrode '4 :is located ion-the opposite race o the block Thecollectorelectrode 3 i's'biased -positively with-respect to-the baseelectrode ikby 71a variable--13. .6; potential source "5, inseries witha load-impedance The current which flows due to this .-positi-ve.voltlage bias is defined herein as a positive urrent bias. -If anelectrode is-biased .-negatively-;-with;

' respect tothe "base electrode, the current-which These characteristicssuggest the desirability of I findingsome way toutilize-the transistor,or a similar deviceasthe'bas'ic element of a triggered type relay.

It is, accordingly, -an object of my invention to provide animprovedtriggered typerelay apparatus for use at very low power levels whichshall utilize, as its basic element, a device comprising-abody or blockof semi-conductive material having three electrodes associatedtherewith.

flows as a result "of thlsbias is herein defined v {asanegativecurrent-bias. If a-plot is madewi-th collector current, I, as,ordina'te,-and collector voltage,=V, as abscissa, the -result will :beacol lec'tor characteristicdiavingea. pejak voltage-such as isfsh'own bythe cur-veil of -Fig. 2 or the draw-= i-ng. The --valuey-of*-the'collector characteristic peak voltage in the positive direction:is-knownto besdependent upon the location and pressure yOf' the collector probeon the inclusion. if the-c01- lector vprobe is properly-located, thispeak can be made to substantially disappear by increasing the probepressure. The voltage of thispeakzis' also affected by ,the {temperatureofitghe probeinclusion iunction region andxbv intensity ofr z e it Vductor band) falling in the area near the probe-inclusion J'unction. Itis from this latter effect that the name photo-peak was derived. It isknown empirically that the collector characteristic peak always occursat substantially the same collector current magnitude. A fullysatisfactory explanation for this phenomena has not as yet been found.It is generally accepted, however, that light and temperature affect thenumber of current carriers present in the semi-conductor material (holesin the filled band, electrons in the con-'- For the theory of conductionin solids as it is now understood, reference is made to such works asTorrey and Whitmer, Crystal Rectifiers, McGraw-I-Iill, 1948, and adetailed discussion therefore will not be attempted here.

The photo-peak diode difiers from the ordinary semi-conductor diode, inwhich the semiconductor is all either P type or N type, in that thephoto-peak diode has a high resistance inboth"the'positive and negativedirections, in the region from the origin substantially to the peaks.This region is indicated as being'between the points a and b on curve Aof Fig. 2.

The back resistance (the probe-semi-conductor contact resistance in thenormally low current direction). of a' pure N or P typesemi-conductorcan be varied by placing a second probe electrode near thecollector electrode and injecting either holes or electrons respectivelyinto the semi-conductive material. of transistor action. In an ordinaryP type transistor, the back resistance is caused to de- This is theprincipal crease by the injection of electrons (which is done by biasingtheemitter electrode negatively with respect to the base electrode, whenthe col lector voltage is positive). In the case ofan N type transistor,the same effect is obtained'by injection of holes (which is done bybiasing the emitter electrode positively with respect to thebaseelectrode'when the collector voltage is negative); 'Thus it is notedthat in the case offP type semi-conductive materiaL'the' back resistanceis decreased by the injection of electrons.

i have discoveredthat if the collector probe pressure on a photo-peakdiode is adjusted so that the collector characteristic peaksubstantially disappears, and a second probe is placed on the N typematerial near the N-P- boundaryftha't the peak can be caused to reappearby causing electrons to flow from the second probe into the N typemateriaL This action is anomalous to the expected result, because itmeans: that the back resistance of P type materialhas been increased,rather than decreased, by electron injection. I have also found that asthe negative bias on the second probe is continuously increased, (moreelectrons injected intothe P type material through the barrier betweenthe N type material and the "P type material) the voltage of the peak ofthe collector characteristic curve increases, reaches a maximum, andthen decreases. On the other hand, if the pressure and location of thecollector probe is' adjusted such that a peak appears initially in thecollector characteristic, the magnitude of this peak can be'made todecrease by injection of hole's'from the second probe into the N typematerial. I have found'further that the breakdown voltage in the backdirection of an ordinary semi-conductor diode can be varied by currentcarrier (holes or electrons, as the case may be) injection} Inaccordance with thebroad aspects of my invention, I utilize thediscovery that the collector characteristic peaks, in the case of aphoto-peak semi-conductor diode (or the voltage at which breakdownoccurs in the back direction, in the case of an ordinary semi-conductordiode), can be caused to vary by injection of current carriers from asecond probe, to provide a novel and improved triggered type relaydevice.

It is to be understood that the principles of my invention may beapplied to various forms of appropriate semi-conductive devices. Inorder that my invention be clearly understood, however, I will describeit in connection with specific embodiments in which a semi-conductivedevice taking the general form of the so-called type A transistor, isutilized.

My invention, together with other objects and advantages thereof, willbe best understood from the following description, when read inconnection with the accompanying drawing, in which:

Figure 1 is a schematic diagram showing a conventional photo-peak diode;

Fig. 2 is a curve showing the collector characteristic of a photo-peakdiode such .as that of Fig. 1; I

Fig. 3 is a schematic diagram showing a preferred embodiment ofmyinvention;

Fig. 4 is a curve showing the collector diode characteristic of thesemi-conductive device of Fig. 3 for various conditions;

Fig. 5 is a schematic diagram showing a further embodiment of myinvention; and

Fig. 6 is a curve showing the collector diod characteristic of thesemi-conductive device oi Fig. 5, for various reasons.

With reference to Fig. 3, a triggered type relay device maybeconstructed in accordance with my invention by utilizing a block ll ofan N] stype semi-conductive material having on one race thereof a smallP type inclusion l3; .The' semi-conductive material may be of anysuitable type but is preferably germanium. The preferred method offorming the P type inclusion is by high energy particle bombardment ofan N type semi-conductive block. How

ever, if it is desired, N type crystal blocks having P type inclusionscan be selected from a large melt of semi-conductive material. A pointcontact collector probe 15 is located in contact with the inclusion I3and near the PN'- boundary'of the semi-conductive block I l. A baseelectrode I1 is placed contiguous to the opposite face of the block i lin such a manner as to secure a relatively large electrical contactarea. A suitable output impedance is having terminals l9,

2!, is connected in series with a source of variable potential 23between the collector electrode l5 and the base electrode [7. Thisvariable potential is shown as a potentiometer 25 shunted by a battery2'! to place a positive bias on the collector electrode l5. However, anA. C. collector bias potential may be used in some applications, as willbe hereinafter more fully explained. A second point contact electrode29, which will be hereinafter referred to as the emitter electrode, isplaced in contact with the "N" type material H proximate to thecollector electrode 15. An input impedance 3! having terminals 33, 35 isconnected in series with a variable source of D. C. potential 31 betweenthe emitter and base electrodes 29, ll. This D. C. potential is shownfor convenience as a potentiometer 39 shunted bya pair of seriesconnected batteries 40, 4!.

of the potentiometer 39 is connected to the lower The sliding contact 48zeta-ace mplitrrimpedancc terminal 351- the battery junction: 44? is'c'onnected' to. the 'i'rbas'e electrode 112"? dlieipola'rity of :thesource 2321 fisi-made selectively: positive or negative depending uponthe position 'iif :theipotentiometer :sliding contact #6 It isemphasizedthat "the arrangement justdescribedimschematic and isiintendedonly .to serve ian ai'dvin the understanding'of some-of the pdssi-bleiorms which my inventionmay take, and ismot'intended' to-necessarilyrepresent any pairticularcommercialiorm whichanyinvention may take.

"jThe woperation fof :the arrangement; shown 'in Fig. 3-w'i1l be bestexplained by reference tothe curve :n'fvFig. -4= in: which Ihave,plotted collector currentmlg asordina-teand' the collector voltage Shies, the abscissa, for :the various operating conditions :A 103(1111118,B, has been drawn ."for a collector voltage of E01 :andxaload impedanceof X-fohms; *n-ploa'd-line, C, :has been drawn for agcollector voltageEczanda-load impedance of Xphms; lf- :itwis 'desireduto produce acontrol pulse :atathe terminals I9, 21 of the output ii-mpedance 1:8,the collector -probe I isadjusted in location and pressure such that inthe absence ofanemitter-biasthe peak in the diode characteristicsubstantially disappears, as shown 'by curve B of -Fig. .4. Thepotentiometer sliding centact 46=is=then.-located-so as to place anegatiye bias ionthe emitter electrode 29, causing the peak to reappear;This negative bias is adjusted sothat the collector characteristiccurve- E is intersected by the load line at at least -threepoints c, c,th'e point of highest voltages beingyjust-belowthe voltage "of the mayto .anew operating pointotrlatively =high magnitude;' as determined bythe load line, .B, at c. This jump in collector current magnitudeis'jsubstantially instantaneous, I have found inactual practice that thecollector current will jump from a magnitude of 1 mill'iampere to aboutIO- rnilliamperes' iinflless than 5} of .a microsecond. The voltagechangeiin .theleniitter circuit required to cause this triggerIaction'is somewhat'less' than 1 volt.

jQnce'lthe'circuit' has been triggered, lit can'be reset after restoringthe'in'iti'al .emi'tter'bias, by reducing the collector voltage.sufiici'ently that the load line, 0, will now interesect the collectorcharacteristic (curve Elat only one point; g. Once the collectorvoltagehasi'been suihciently reduced,'th'e circuitis' resetsubstantially instantaneously (the reset time being of the sameorderof-magnitude'as the trigger time, .or less than i 'of amicrosecond). The collector; voltage can be 'automatically're'ducedtoreset thecircu'it by various conventional means. For example, thecapacitor 45, resistance '43 arrangements'hown in Fig; .3 servesthi's'purpose. Theresistance la is inserted .betweenthe base electrodeIll and the negative terminal of the collector potential source 23, andthe capacitor 45 is shunted'across the potential source 23 andthetresistance=43z Inthis case the circuit may/be 'usedcas arelaxationosclllator. .vSuch an oscillator maybeeith er pulsed or freerunning,':by proper adjustmentof either emitter pr collector bias. Thecircuit'may also be 1made-.to. :reset automatically by the use ofanwalternating current collector potential.

- Ifithe emitterbias :is initially made-.sufficiently negative, .themaximum. collector characteristicrp'eak voltageiindicated by curve G ofFig. 4 mayibe reachedQso :that increased negative bias willicausie:afdecrease the peak voltage. The negativeiemitter bias maybeiincreasedsufficient-' lythat .the-ipeak voltage will :decrease to correspond tocurveE. .In this :case the. circuit can be itriggeredsby placing acrossthe input impedanc'e terminals .33, a negative trigger pulseofiisufficientcmagnitude to further reduce the collector characteristic:peak .to correspond to cur-veil; :The collector current will then jumpfIOiH'Ei-IElfiilVGlY low:magnitude c to a relatively hig'hzmagnitude c.Also,.if .the emitter is biased negatively so that the maximum collectorcharacteristicipeakzvoltageappears (curve Gr, Fig. 4) andrth'eacollector voltage is set so that a load line, B, will intersectthe collector characteristic .peakatpoints sand t, just -below the peakvoltage, :then :the .device maybe triggered by either :a positive ornegative pulse applied across theiinput' impedance terminals 33, 35. Itis appare'ntthat the arrangement of Fig. -3 may be adapted to .operateas any conventional trigger circuittwithinits range of parameters. Itmay also be operated as a relaxation oscillator, or a ipulseigenerator.If it :is desired, a P type semi-conductive block having .an N-Pinclusion onloneiface thereof may be used with the same results, exceptthat all lpolariti'e's will then be reversed. 3' I .Eor-another'type oroperation :of the arrangement of Fig.f3, the pressure of the collectorelectrodermayrbeadiusted (decreased) so that initial- 1y 2. peak appearsin the collector characteristic. In this case'lthe potentiometer slider46 is adjusted so as'to placea positive'bias on the emitter electrode29; This positive bias tends to decrease the magnitude of the collectorcharacteristic peak voltage and it may be adjusted so that thepeakappears-as curve E of Fig. 4. 'If a positive trigger pulse is nowapplied to the input impedanceterm'inals 33,'35 and is of suchmagnitudeas-to reduce the collector-ch'aracteristic peak voltagesufiiciently that the load line B, will in tersect the collectorcharacteristic curve F, at only one point e the circuit'will again betriggered; and the :ccllector current will jump instantaneouslyfr'om' arelativelv'low to 'a relativelyhigh magnitude as 'inthe case previouslydescribed. It' is'possible to use a P type semi-conductive block with anN type inclusion in the same manner 'as in the operation last described,ex-

cept that'all polarities would be reversed.

"in Fig.5 there is'shown an ordinary transistor comprising abl-ock-d'lof N type semi-conductin'g' aterial and having emitter, collector, andbase lectrodes 4955!, 53'associated therewith in the conventionalmanner. An input impedance 55 havi-ng terminals 51, 5-9 is connected'inseries with a source iii of variable D. C. potential shown as apotentiorneter'fit in shunt with a battery between theemitter and baseelectrodes '19, 53. An output impedance 61 having terminals 69, H isconnected in series with a source 13 of variable D. C. potential shownas a battery id in shunt with a "potentiometer '11 between the collectorand base electrodes 5|, 53. To operate the 'arnan'gement shown in Fig. 5as 'a'trigger circuit,

the a'co'llector #electrode'iil is biased negatively to 7 apredetermined value, Ecs, as indicated on the graph of Fig. 6. A loadline, H, has been drawn in Fig. 6, assuming an output impedance of Xohms, and a collector bias of E03. Another load line K, has been drawnfor a collector bias of E04 and an output impedance of X ohms. Theemitter bias is then made sufliciently positive to cause the collectorcharacteristic peak voltage curve, L; to intersect the load line, H,atat least three points .h, k, n, Fig. 6. The circuit can then betriggered by the application of a positive pulse to the input impedanceterminals, 51, 59 of suificient magnitude to reduce the collectorcharacteristic peak voltage sufficiently that it corresponds tocurve,'M,which is intersected by the load line, L, at only one point N. Thecollector current willthen jump substantially instantaneously from itsoperating point of relatively low collector current magnitude h to anoperating point 11. of relatively high collector current magnitude. Thecircuit can be reset, after the initial emitter bias has been restored,byreducing the collector voltage sufiiciently that the load line, K,intersects the collector characteristic curve, L, at only one point m.If a D. C. collector potential is used, the circuit may be reset by acapacitor iii-resistor l9 arrangementas shown in Fig. 5. The resistance19 is inserted between the base electrode 53 and the positive terminalof the'col lector potential source 13 and the capacitor 16 is shuntedacross the resistance 19 and the potential source 13. Such a circuit maybe operated as a relaxation oscillator. An alternating current collectorpotential could also be used but is not preferred, because the forwardresistance is sufficiently low to cause power dissipation of undesirablemagnitude on the positive half-cycles of the A. C. 1collector potentialsupply. The ordinary transistor action just describedmay be adapted foruse, in accordance with my invention, as any conventional type triggercircuit, as a relaxation oscillator, or a pulse generator. If itisdesired, a P type crystal'may be used with the same results,exceptthat the polarities wil bereversed.

In accordance with another aspect of my invention, it is not necessaryto apply an external trigger pulse to the input impedance in thearrangements hereinbefore discussed with reference to Figsr3 and 5.v Ithas been stated above that the value of the collector peak voltage or aphoto-peak diode is aifected by the number of current carriers presentin the vicinity of the probe contact. Since temperature is one of thequantities which afiects the number of current carriers present, it isclear that if the collector voltage were set at a predetermined valueand the temperature slowly raised until the voltage of thepeak droppedbelow this value, the collector current would be suddenly increased.However, individual semi-conductive crystals vary considerably in theirtemperature response, and most of these have a sufficiently highthreshold of the temperature effect that their use directlyastemperaturetrigger devices would be very limited. However, theresistance in the back direction of an N type semi-conductor diode is aninverse function of temperature, for temperatures belows the intrinsicrange of the semi-conductor. Therefore, for example, a circuit arranged,such as shown in Fig. -3 may be used as a thermally triggeredrelaydevice. One way of doing this, is with the collector bias set to Eci,Fig. 4,-tc adjust the collector probe pressure and location so that thecollector characteristic, peak temperature of the semi-conductor in thevicinity of the emitter probe is lowered slightly, so that theresistance in the emitter circuit is increased to decrease the emittercurrent, and in effect, decrease the negative emitter bias suificientlyto cause the collector characteristic peak voltage to be reduced tocorrespond to curve F, Fig. 4, the device will trigger. With theconditions as just described except that the negative emitter bias isincreased sufiiciently that the maximum collector characteristic peakvoltage is exceeded and'the peak decreased with increasing bias tocorrespond to curve E, Fig. 4, the device will trigger when thetemperature in the emitter probe vicinity is raised sufi'iciently tocause, in efiect, increased negative'emitter bias to bring the collectorcharacteristic to correspond to curve F. Also, if the emitter is biasednegatively so that the maximum collector characteristic peak voltageappears (curve G, Fig. 4) and the collector voltage is set so that aload line, B, will intersect the collector characteristic peak at pointss and if, just below the peak voltage, then the device will be triggeredby either an increase or a decrease in the temperature of the emitterprobe contact region. Further, if the collector probe pressure andlocation is initially adjusted so that a peak appears in the collectorcharacteristic, and the emitter bias is then adjusted positive so thepeak is reduced to correspond to curve E of Fig. 4, then a rise ineither the emitter or collector probe temperature will further lower thepeak to correspond to curve F, of Fig. 4, and will cause the device tobe triggered In the three cases described immediately above, a P typesemi-conductive block having an N type inclusion could also be used, butthe polarities would be reversed.

An ordinary semi-conductive diode, instead of V in which this could bedone are believed to be gered relay device constructed in accordancewith the teachings of my invention, will provide a discrete currentstepjwithout making a physical electrical contact.

I wish to point out, for reasons of clarity, that in all caseshereinbefore described, in order to establish an initial operating pointof loWcurrent magnitude, it is necessary that the collector diodecharacteristic upon which'it is desired to operate be first obtained, byadjustment of emitter bias, or otherwise, as the case maybe, before thecollector bias voltage is applied.

I am aware that many modifications of the embodiments shown anddescribed are possible without departing from the scope of my invention, I desire, therefore, to be limited only as is necessitated by theprior art and the spirit of the appended claims.

I claim as my invention:

l. A relay device, comprising a block of "N type semi-conductivematerial having a smallP" tyne. inclusion. one ace thcreoi. n emitt relectrode; pla ed on. N t pe ater al. n ar a d inclusion, a ollector.electrode p ace Q said inc1uslon,.a.;base .clcctrode. plac o e. p o tface, o id block. an inputc r uit c m r s g ansinputimp dance conne in.scr e i a source of adjustable. ne ative D. C- biaszp t n albetweensaid emitter and base, electrodes, and an output impedance connected inseries with a positive. D. 'C...bi as potential between said collectorand base electrodes.

1 r l y devic c mprising a b ock o typesemi-conductive,materialhaving asmall P type inclusion on one face thereof, an emitter probe placed on.said block, near said inclusion, a collector 'probe. placed on said.inclusion, a base electrode placed on the opposite face of saidblock,"means. for biasing said collectorprobe posi-. tive witnrespect;tosaid base electrode, th diode volt-ampere:characteristic .of saidcollectorbein'g f h p orp kype, thelocaticn andprcss rc of.saidcollector electrode with respcctto said inclusion-being such thatthe photo-peak of said collectorcharacteristic is removed, and rneansforapplying bias. to make said emitter electrode negative with respect tosaid base electrode, w-hrebyitha peak of said collector characteristicis caused tolreappear.

.3. A1 relay device, comprising a block; of N typeasemi-conductivematerial having a,..sma1 "F-"type inclusion on one face thereof, an cm.12 probe placed on said block, .ncar s id. inclusion, a collector probevplaced on said inclusion a ase electrode placedon the opposite faceofsaidblock, meansafo-r biasing said collector probe positive with respectto. said base electrode, the diode characteristic of said collectorbeing of the photopeak type, thelocation and pressure of said 001-lectorelectrode with respect. to said inclusionbeing such that thephoto-peak of said collector characteristicis removed, and means forapplying biaatomakasaid emitter electrode negative withrespectto..s,aidr.basc electrode, whereby'thc P681 15 of saiducoll'ectorcharacteristic L's-appear and as saidl'ast-mientionecllbias is madestill-,more negative; Lsaidcollector characteristicgreachcs a marrimumpeak, and as. saidnesatiyc bias is. fur h rincreased; saidcollectorscharacteristic recedcs. from the maximum peak magnitude.

4 .'.In combination, a block .of N type semiconductive material havinga. small. 53 type,. in.- clusion'on'. one. face. thereoia ccllectorprobe placeddn.cont'actxivith said inclusiomab se electrodedncontactwith anotherv faccof sa d. bl k. means. for biasing. said collectorprobe positive with respect. tolsaidbase electrode, the location andcontact: pressure .ofsaid collector probe being ad'jnstedso thatnojvoltage peak appears. in the collector: rcharacteristic, means. forcontrolling sai'dlcollector.characteristic .to produce voltagepairs-therein, said means including an emitter electrodei placed on.saidrblock near said inclusion and a1-bia s;.source which-may be appliedto; bias said emitter electrode negative with respect to saidbase-electrode toa selectable degree...

"5. A rel'a y'device, comprising a collector probe in contact-with asmall P type inclusion in a block of N type semi-conductive materialhaving a base electrode which is biased negatively with respect to said---col1ector electrode, the pressure and locatio n of saidcollector'probe having been adjusted so that'no peak appears in thecollector characteristic, a load impedance incir-v cult: with saidcollector probe, an emitter elec-' Mode in contact with said blocknearsaid includucinssaidemit er biasto a efasub lac-tor current, a d meinstantarlcotisjnmpatoan p at ishc llac orcnrl 1.. .v :ter reducepsaidcollector cl sum icntly lac-cause a r t. point ofrelafively low.collccor =1 Y 7.. A r lay device, comprising a block. or ff:l .T:.-'ype semi-conductive material. asmah. .B; tyne. inclusion on. one face;of. said bl ck. :a. collectcr clcctr dein contact. with. said .mGl-MiQX-b; a ham electr de cpntact-withthe. oppcsita iaca. said. lock, the.location and contact. pressurc .of-;said ccllector electrode heins..adiustedsuch. 'that.nc.= p ak appears. in. the diode. characteristic of-.said-. collector electrode, an emitter electrode in mmtact witniilrlzty pelmatcrial..onsaid-blocl; near said; inclusion, a. source-of .D.;C. notentiarrcr biasin aid: emitter electrode negatively with. respectto said; base electrode, a load inmcdanca in circuit; with-saidcollector electrode, means :for: biasinasaid col-lectorielectrode.positivelyrvithirea. spect: to. said :base electrode; whereby an.opc'ra. ating point- .ofirelatively low load impedance; cur-.1 rentisestablished on said collector characteristic, an inputimpedance incircuit with said emitter electrode; means. tor applying a momentarycpoatentialftosaid; input impedance insa sense, de? pending upon themagnitude iOf emitter negative. bias; such. that. the load.il'nped'ance' current. substantially Jinstantaneonsly rise. to a.relatively high magnitude, Blldi means. for reducing fsai'gi collectorpositive; bias suffi'ciently' .to returngsaidi load impedance current.to. a. relatively lowimagnituda V .3; A relay-device, comprising a blockof EPc type .semiaconductiveimaterialhaving asmall "Ni" type'incllisionjon one. tacc thereof, a probe placedon said block; nearsaiid inclusion,a.

photo-peak p the; location. and .nr ssu Said qqllectorialectro rcsnc o.-clusiqn; being: such. "that. the mammals collector characteristic isremoved, and means for applying bias to makesaid emitter electrodepositive with respect to said base electrode, whereby the peak of-saidcollectorcharacteristic is caused tore-appear. 7 w

9'. In combination, a block-of P type semiconductive material having asmall N type inclusion on one face thereof, a collector probe placed incontact with said inclusion, a base electrddein contact with anotherface of said block, meansfor biasing said collector probe negative withrespect to said base electrode, the location and contact pressure ofsaid collector probe being adjusted so that no voltage peak appears inthe collector characteristic, means for controlling said collectorcharacteristic to produce voltage peaks therein, said means including anemitter electrode placed on saidblock near said inclusion and a bias'source-which may be applied to bias said emitter electrode positive withrespect to said base electrode to a selectable degree.

10.1A relay device, comprising a block of P typesemi-conductivematerial, a small N'type inclusion on one face ofsaid-block, a collector electrode in contact with said inclusion, a baseelectrode on the opposite face of said block, said collector electrodebeingadjusted in location and contact pressure such that no peaks appearin the collector characteristic, an emitter electrode located on Ptype'material near said inclusion,

'means for biasing said emitter electrode positive with respect to saidbase electrode, said emitter bias being so adjusted that a peak appearsin the collector characteristiq'means for biasing said collectorelectrode negative with respect to said base electrode to establish anoperating point on said collector characteristic of relatively lowcollector current, and means for momentarily reducing said emitter biasto cause a substantially instantaneous jump to an operating point ofrelatively high collector current, and means to thereafter reduce saidcollector electrode negative bias sufficiently to cause a return to saidoperating point of relatively low collector current.

all. A relay device, comprising a block of P type-semi-conductivematerial, a small N type inclusion on one face of said block, acollector electrode in contact'with' said inclusion, a base electrode incontact with the opposite face of said block, the location and contactpressure of said, collector electrode being adjusted such that no peakappears in the diodecharacteristic of said collector electrode, anemitter electrode in contact with fP type material'on said block nearsaid inclusion, a source of D. C. potential for biasing said emitterelectrode positively with respect to said base electrode, a loadimpedance in circuitowith said collector electrode, means for biasingsaid emitter electrode negatively withrespect to said base electrode,whereby an operating point of relatively low load impedance current isestablished on said collector characteristic, an input impedance incircuit withisaid emitter electrode, means for applying a momentarypotential to said input impedance in a sense, depending upon themagnitude of emitter positive bias, such that the load impedance currentwill substantially instantaneously rise to a rel-. atively highmagnitude, and means for reducing said collector negative biassufiiciently to return said load impedance current to a relatively lowmagnitude.

12. In combination, a block of Ntype semiconductive materialhaving asmall? type inclusion on one face thereof, a collector probe placed incontact with said inclusion, a base electrode in contact with anotherface of said block, means for biasing said collector probe positive withrespect to said base electrode, the loca tion and contact pressure ofsaid collector probe being adjusted so that a voltage peak appears inthe collector characteristic, means for controlling said collectorcharacteristic to remove voltage peaks therein, said means including anemitter electrode placed on said block near said inclusion, and a biassource-which may be applied to bias said emitter electrode positive withrespect to said base electrode to a selectable degree. c

13. A relay device, comprising a block of N type semi-conductivematerial, a small 1? type inclusion on one face of said block, acollector electrode in contact with said inclusion, a base electrode onthe opposite face of said block, said collector electrode being adjustedin location and contact pressure such that peaks appear in the collectorcharacteristic, an emitter electrode 10- catedon N type material nearsaid inclusion, means for biasing said collector electrode positivewith'respect to said baseelectrode, means for biasing said emitterelectrode positive with respect to said base electrode, said emitterbias being so adjusted that a peak in the collector characteristicestablishes an operating point of relatively low collector current, andmeans for momentarily increasing said emitter bias so cause asubstantially instantaneous jump to an operating point of relativelyhigh collector current, and means to thereafter reduce said collectorelectrode positive bias sufficiently to cause a return to said operatingpoint of relatively low collector cur-rent.

14. A relay device, comprising a block of N 7 type semi-conductivematerial, a small P type inclusion on one face of said block, acollector electrode in contact with said inclusion, a base electrode incontact with the opposite face of said block, the location and contactpressure of saidcollector electrode being adjusted such that-a peakappears in diode characteristic of said collector electrode, an emitterelectrode in contact with N type material on said block near saidinclusion, a source of D. C. potential for biasing said emitterelectrode positively with respect to said base electrode, a loadimpedance in circuit with said collector electrode, means for biasingsaid collector electrode positive with respect to said base electrode,whereby an operating point of relatively low load impedance current isestablished on saidcollector characteristic, an input impedance incircuit with said emitter electrode, means for applying a momentarypositive potential to said input impedance, to cause said load impedancecurrent to rise substantially instantaneously to a relatively highmagnitude, and means for thereafter reducing saidcollector positive biassufiiciently to return said load impedance. current to a relatively lowmagnitude. 7

15. In combination, a block of P type semiconductive material having asmall N type inclusion on'one fa'ce thereof, a collector probe placed incontact with said inclusion, a base elec-' trode in contact with anotherface of said block, means for biasing said collector probe positive withrespect to said base electrode, the location and contact pressure ofsaid collector probe being adjusted so that a voltagepeak appears in thecollector characteristic, means for controlling said collectorcharacteristic to remove voltage creases peaks therein, saidmeansincluding an emitter electrode placedon said block near said inclusionand a bias source which may be applied to bias said emitter electrodenegative with respect to said base electrode to a selectable degree. I

'16. A relay device, comprising a block of P type semi-conductivematerial, a small N .type inclusion on one face of said block, acollector electrode in contact with said inclusion, a base electrode onthe opposite face of said block, said collector electrode being adjustedin location and contact pressure such that peaks appear in the collectorcharacteristic, an emitter electrode located on P type material nearsaid: inclusion, means for biasing said collector electrode nega-' tivewith respect to said base electrode-means for biasing said emitterelectrode negative with respect t'osaid base electrode, said emitterbias being so adjusted thatapeak in the collector characteristicestablishes an operating point of relatively low collector current, andmeans for momentarily increasing in said emitter biasto causea-substantially instantaneous jumpto an operatingpoint of relativelyhigh collector current, and means to thereafter reduce said collectorelectrode negative bias sufificiently to cause a return to saidoperating point of relatively low collector current.

1'7. A relay device, comprising a block of P type semi-conductivematerial, a small N type inclusion on one face of said block, acollector electrode in contact with said inclusion, a base electrode incontact with the oppositeface of said block, the location and contactpressure of said collector electrode being adjusted such that a ingpointof relati'vely low load impedance current is established on saidcollector characteristic, and input impedance in circuit with saidemitter electrode, means for applying amomenta'ry negative potential tosaid input impedance, to cause saidload: impedance current to risesubstantially instantaneous to "a relatively high magnitude, and meansfor thereafter reducing "said collector negative bias sufficiently toreturn said load impedance current to a relatively low magnitude. I

18-. A thermostatic device, comprising a block of N type semi-conductivematerial, a small P type inclusion on one 'face of said block, acollector electrode in contact with said inclusion, a base electrode onthe opposite face of said block, said collector electrode beinginitially adjus'tedin location and contact pressure such that 'no "peakappears in the diode characteristic of said collector electrode, anemitter "electrode located on- N type materialne'ar said'inclusion,means-for biasing said emitterelectrode negative with-respect to saidbase electrode, said "emitter-bias being so adjusted theta peak apanoperating point of relatively low collector cura base'electro'de on, theopposite face of "said block, said collector electrode being initiallyadjusted in locationand contact. pressure such that no peak appears inthe diode characteristic of said collector electrode, an emitterelectrode located on N type material near said inclusion, means forbiasing said emitter electrode negative with respect to said baseelectrode, said emitter bias being so adjusted that the peak which iscaused by said emitter bias. to appear in said I collectorcharacteristic has passed through a maximum and decreases in magnitudewith increased emitter bias, means for biasing said collector electrodepositively toa predetermined magnitude with respect to said baseelectrode, said base being onlysli'ghtly greater vinmagnitude than thevoltage-between saidgcollector and base electrodes, to establish. anoperating. point of relatively low collector current, whereby a smallincrease of ambient temperature will lower the voltage of said peak toamagnitudelessthan the'voltage between said collectorandbase-'electrodes, and an operating, point of relatively high collectorcurrent will be substantially instantaneously established;

20. A thermostatic device, comprising ablock of ,N type semi-conductivematerial, a: small P type inclusion on one face of said :block, acollector electrode in contact withssaid inclusion, a base electrodeincontact with theopposite face of said block, the location and contactpressure of said collector electrode being initially so-adjusted that nopeak appears in its diode-voltampere characteristic, an emitterelectrode in contact with Ntype, material on said block near saidinclusion, means for biasing said. emitter electrode negatively withrespectv to said base electrode, a load impedance in circuit-with saidcollector electrode, said emitter negative bias being adjusted such thatthe collector characteristic peak is of maximum magnitude, means forbiasing said collector electrode to a positive magnitude with respect tosaid base electrode such that the load line will intersect saidcolelector characteristic at points just below said maximum peakmagnitude toestablish-an operating point of relatively low load impedance current,whereby a slight change in emitter probe contact temperature in eithersense, will cause said collector characteristic peak to be reduced to amagnitude such that the load line will intersect said collectorcharacteristic at; only one point, whereby an operating, point ofrelatively high load impedance currentis substantially instantaneouslyestablished.

21. A- thermostatic device, comprising a block of PT-typesemi-conductive material, a small N type inclusion on one face of saidblock, a collector electrode in contact with said. inclusion, a. baseelectrode on the opposite face of said block,.said-collector electrodebeing'initially adjusted in location and contactpressure'such that nopeaks appear in its diodevolt-ampere characteristic, an emitterelectrode located on tude.

P type material near said inclusion, means for sect said collectorcharacteristic at points just below said peak magnitude to establish anoperating point of relatively low collector current, whereby a smallincrease of ambient temperature will lower the voltage of said peak to amagnitude less than said collector bias, and an operating point'ofrelatively high collector current will be substantially instantaneouslyestablished.

22. A thermostatic device, comprising a block of N type semi-conductivematerial, a small P type inclusion on one face of said block, acollector electrode in contact with said inclusion, a base electrode onthe opposite face of said block, means for biasing said collectorelectrode positively to a predetermined magnitude with respectto saidbase electrode, said collector electrode being initially adjusted inlocation and contact pressure such that a peak appears in.

its diode volt-ampere characteristic, an emitter electrode located on Ntype material near said inclusion, means for biasing said emitter electrode positively with respect to said base electrode, said emitter biasbeing so adjusted that the collector peak is of a magnitude such that aload line will intersect said collector characteristic at points justbelow said peak magnitude to establish an operating point of relativelylow collector current, whereby a slight increase in ambient temperaturewill lower said peak to a magnitude such that the load line willintersect said characteristic at only 'onepoint, and an operating pointof relatively 'high collector current will be substantiallyinstantaneously established.

23. A relay device, comprising a block of N type semi conductivematerial having emitter and collector probes located in proximity on oneface thereof and a base electrode in contact with the opposite face, asource of D. C. bias in circuit with said emitter probe, said emitterbias I being adjusted positive with respect to said base electrode andof magnitude so as to establish a first collector peak voltagecharacteristic, said collector bias being adjusted negative with respectto said base electrode and of magnitude such that a load'line willintersect said collector peak characteristic at three points,'and meansfor increasing said emitter bias sufficiently to establish a secondcollector peak characteristic which is intersected by said load line atonly one point, whereby the collector current'will jump instantaneouslyto a comparatively large magni- 24. A relay device, comprising a blockofN type semi-coductive material having emitter and collector probeslocated in proximity on one face thereof and a base electrode in contactwith'the opposite face, a source of D. C. bias in circuit with'saidemitter probe, said emitter" bias being adjusted positive with respectto said base electrode and of magnitude so as to establish a firstcollector peak voltage characteristic, said collector bias beingadjusted negative with respect to said base electrode and ofmagnitudesuch that the load line will intersectsaid collectorpeakcharacteristic atgthree points, means for in? creasing said emitter biassufiiciently to -establish a second collector peak characteristic whichis intersected by said load line at only one point, which is ofrelatively high collector current magnitude, whereby the collector.current will jump instantaneously to a comparatively large magnitude,means for restoring the original-magnitude of emitter bias, means forthereafter reducing said collector bias sufiiciently that the load lineis;moved to intersect the collector peak characteristic at only onepoint, which is of relatively low collector current magnitude, whereby'the collector current will be reduced to theinitial magnitude. l

25. A relay device, comprising a block of P type semi-conductivematerial having emitter and collector probes located in proximity onone, face thereof and a base electrode'in contact with the oppositeface, a source of. D. C. bias in circuit with said emitter probe, saidemitter bias being adjusted negative with respect to said base electrodeand of magnitude so as to establish a first collector peak voltagecharacteristic, said collector bias being adjusted positive with respectto said base electrode and of magnitude such that the load line willintersect said collector peak characteristic at three points, and meansfor increasing said emitter bias sufiiciently to establish a secondcollector peak'characteristic which is intersected by said load line atonly one point, whereby the collector current will'jump instantaneouslyto a comparatively large magnitude.

26. A relay device, comprising a block of P type semi-conductivematerial having emitter and collector probes located in proximity on oneface thereof and a base electrode in contact with the opposite face, asource of D. C. bias in circuit with said emitter probe, said emitterbias being adjusted negative with respect to said base electrode and ofmagnitude so as to establish a first collector peak voltagecharacteristic,' said collector bias being adjusted positive withrespect to said base electrode and of magnitude such that the load linewill intersect said collector peak characteristic at at least one point,means for increasing said emitter bias sufficiently to establish asecond collector peak characteristic which is not intersected by saidload line, where'- by the collector current will jump instantaneously toa comparatively large magnitude, means for restoring theorginalmagnitude of emitter bias, means for thereafter reducing saidcollector bias sufficiently that the load lineintersects the collectorpeak characteristic at only one point, which is not a tangent, wherebythe collector current will be reduced to the initial magintude.

27. A thermostatic device, comprising a body of N type semi-conductivematerial containing an inclusion of P type semi-conductive materialpartially exposed on the external surface of said body, an emitterelectrode placed on the N type material near said inclusion, a collectorelectrode placed on said inclusion, abase electrode placed on said Ntype material and spaced from said emitter electrode, said collectorelectrode being initially adjusted in location and contact pressure suchthat no peak appears in the diode characteristic of said collectorelectrode,

means for biasing said emitter electrode negative with respect to saidbase electrode, said emitter electrode being so adjusted that a peakappears in said collector characteristic, means for biasing saidcollector electrode positively to a predetermined magnitude with respectto said .base electrode, said peak being only slightly greater inmagnitude than thevoltage between said collector-andbase:electrode, toestablish an operating point of relatively .low collector .current,whereby a small decrease of temperature in the vicinityof the emitterelectrode will lower-the voltageof said peak to-a magnitudeless thanthevoltage between the collector and .baseelectrode, and an operatingpointof relativelyhigh collector current will be. substantiallyinstantaneously established.

,28. A-relay device, comprising a body of N type semi-conductivematerial containing an inclusion .of .P type semi-conductive material,par- .tiallyexposedon the external surface of said body, and emitterelectrode placed on the fN type .material .near said inclusion, acollector electrode placed on said inclusion, a base electrode placed onsaid .N type material and spaced from said emitter-electrode, an inputcircuit comprising .means for .applying .an adjust- -able negative D.0.. current bias through the emit,- ter electrode and means forapplyinga signal to said emitter electrode, and an output impedance connected inseries with a positive D. C. bias potential between said collector andbase electrodes.

29. A relay device, comprising a body of N type semi-conductive materialcontaining anin- .clusion of P type semi-conductive material partiallyexposed on the external surface of said body, a collector electrode incontact with said inclusion, a base electrode placed on the N typematerial, said collector electrode being adjusted in location andcontact pressure such that no .peaks appear in the collectorcharacteristic, an emitter electrode in contact with the N type.material onsaid body near said inclusion, means .for biasing saidemitter electrode negatively with respect to said base .electrode, saidemitter bias being so adjusted that a peak appears in said collectorcharacteristic, aload impedance in circuit with said collectorelectrode, means for bias- .ing said collector electrode positively withre- :spect to said base electrode, .saidpeak being only slightly greater.in magnitude'than the voltage between said collector'and baseelectrodes to establish an operating point of relatively low loadimpedance current on .said collector characteristic, and means forrendering said emitterelectrode less negative with respect to said baseelectrode whereby the load impedance current will .J'umpsubstantiallyinstantaneously to a relatively :high magnitude.

.30. "A relay-device, comprising a, body .of P typesemi-conductivematerial containing an .in- .clusion of N type semi-conductive material1 partially exposed on the external surface of said body, a collectorelectrode in contact withwsaid inclusion, a base-electrodejplaced on theP'type .material, 'said collector-electrode being so adjustedin locationand :contact pressure so that .no peaks .appear in the collectorcharacteristic, an emitter electrode in contact with .P type material onsaid .body near .said inclusion, means .for'biasingsaid emitterelectrode positively with .respect to said base electrode, saidemitter-bias being so adjusted that apeak appears in said collectorcharacteristic, a loadimpedance in circuit with said collectorelectrode, means for biasingsaid collector electrode negatively with re-.spectto said base electrode, said peakbeing only slightlygreater inmagnitude than the voltage 'betweensaid collector and base electrodes toestablish an operating point of relativelylow load impedance -.-currentonnsaidcollector character istic, and means for rendering said emitterelectrode less positive with respect to said base elec-.- trode, wherebythe load. impedance current will jump substantially instantaneously to arelatively high magnitude. I

31. A relay device, comprising a body of N type semi-conductive materialcontaining an.inclusion of P type semi-conductive material partiallyexposed on the external surface of said body, alcollector electrodeincontact with said inclusion, a baseelectrode placed on the N typematerial, said collector electrode ibeing adjusted in location andcontact pressure, such that no peaks appear in the collectorcharacteristic, an emitter electrode in contact with N-ty.pe1materialonsaid body near said inclusion, means forbiasing said emitter electrodenegativelywith respect to said base electrode, saidemitt'erf biasbeingso adjusted that the peakwhich is caused by said-emitter bias, toappear in said collector characteristic has passed through .-a maximumand decreases in magnitude with increasedemitter bias,a load impedancein circuit with said collector electrode, means for biasingsaidcollector electrode positively to a predeterminedmagnitude withrespect to said base electrode, said peak being only slightly greater inmagnitude than thevoltage between said collector andbase electrodes, "toestablish an operating point of rela: tively lowload impedance currenton said,. col,-

'lector characteristic,- and means for rendering.

saidemitter electrode still more negative :with respect-to said baseelectrode whereby the-load impedance current will jump substantially,instantaneously toa relatively high magnitude. s

32. A relay device, comprising a body-of iP typesemi-conductive materialcontaining an mclusion of N type semi-conductive material partiallyexposed onthe external surface of s aid body,-a collector electrode incontact with said inclusion, a base electrode placed on the P-type/material, said collector electrode beingadjusted in location and Icontact pressure such that no peaks-appear in the collectorcharacteristic, an emitterzelectrode incontact-with P :type material onsaid body near said inclusion, means for biasing said emitter electrodepositively with respect ,to said-base electrode,'said emitter bias beingso-adjustedthat the peakwhich is caused, by said emitter bias, to appear.in said collector characteristic has passed through a maximum anddecreases in magnitude with increasedemitter bias, .a load impedance incircuit with said collectorelectrode, means for biasingsaidcollectorelectrode negatively .With respect .to,said base electrode,.said peak being 1 only slightly greater in magnitude than thevoltage'between saidcollectorand base electrodes to establishanoperating point of relatively low load impedance current on .saidcollector characteristic, and means for rendering said -emitter.electrodestill more. positive with respect to-said base; electrode,whereby the load impedance current willjump substantiallyinstantaneously.to.. a relatively high magnitude. r 33. A relay device,comprising-albodycf" type semi-conductive material containing I 1clusion of Pitype semi-conductive material partiallyexposed on theexternal surface of said-body, a collector electrode in contactwith said111C111.- s'ion a base electrode, placed on the N type ma- ,terial, saidcollector electrodebeing ,adjuste'djih location and contact pressuresuch that j a peak appears in-the. collector characteristic L'a'n!mitterlelectro'de in contact with 1jN" 't'yp, age, 9.1

' trodestillmore positive with respect to said base jelectrode wherebythe load impedance current 'will jump substantially instantaneously to arelatively highmagnitude. V

34.;A relay device, comprising a body of "1 type semi-conductivematerial containing an inclusion'oifN type semi-conductive materialpartially exposed on the external surface of said body, a collectorelectrode in contact with said inclusion,,a base electrode placed on the"P type material, said collector electrode being adjusted in locationand contact pressure such that a peak appears in the collectorcharacteristic, an emitter electrode in contact with P type material onsaid body near said inclusion, means for biasing 'said emitter electrodenegatively with respect to said base electrode, a load impedancein'circuit with said collector electrode, means for biasing saidcollector electrode negatively with respect to 'said base electrode,whereby an operatingpoint of relatively low load'impedance current 'isestablished on said collector characteristic, and means forrenderingsaid emitter electrode still -more' negative with respect tos'aid baseelectrode, whereby the load impedance current will jump substantiallyinstantaneously to a relatively high magnitude. e, j -"-f35I.'A relaydevice, comprising a body of N type -semi-conductive material, a baseelectrode, couecmr electrode, and an emitter electrode, in contact withsaid body, a source of D. C. bias in circuit-with said emitterelectrode, said emitter bias being adjusted positive with respect tosaid baseelectrode and of magnitude so as to establish afirst collectorpeak voltage'characteristic, said collector bias being adjusted negativewith respect tosaid base electrode and of magnitude such that the loadline'will inter sect said collector peak characteristic at at least twopoints,

means IQrjrenderingsaid emitter'electrode suffi:

ciently more positive with respect to said-base electrode to establish asecond collector peak characteristic which is intersected by said loadline at only one point, which is of relatively high collectorcurrentmagnitude, whereby the collector current will jumpinstantaneously to a comparatively large magnitude, means for restoringthe initial magnitude of emitter bias, means for thereafter reducingsaid collector bias sufficiently that theload line is moved to intersectthe collector peak characteristic atonly one point, which is of.relatively'low collector current magnitude,

whereby the collector current will be reduced to 20 to saidbaseelectrode that the load line willintersect'the collector peakcharacteristic. at at least two points, means for rendering 'saidemitterelectrode sufficiently more negative withrespect to said base electrodeas to establish a second collector peak characteristic which isintersected by the load line at only one point, which is of relativelyhigh collector current magnitude, whereby the collector current willjump instantaneously to a comparatively large magnitude, means forrestoring the original magnitude of emitter bias, means for thereafterreducing said. collector bias sufhciently that the load line ismovedtointersect the collector peak charactei' istic at only one point, whichisof relatively low collector current magnitude, whereby thecollectorcurrent will be reduced to the initial magnitude.

37. A thermostatic device, comprising a bod of N type semi-conductivematerial containing an inclusion of P type semi-conductive materialpartially exposed on the external surface of said body, an emitterelectrode placed on the N type material near said inclusion, a collectorelectrode placed on said inclusion, a base electrode placed on said N?type material and spaced from said emitter electrode, said collectorelectrode being initially adjusted in location and contact pressure suchthat no peaks appear in the diode characteristic of said collectorelectrode, meansffor biasing said emitter electrode negative withrespect to said base electrode, said emitter bias being so adjusted thatthe peak which is caused, by said emitter bias, to appear in saidcollector characteristic has passed through a maximum and decreases inmagnitude withincreased emitter-bias, means for biasing said collectorelectrode positively to a predetermined magnitude with respect to saidbase electrode, said peak being only slightly greater in magnitude thanthe voltage between said collector and base electrodes, to

establish an operating point of relatively low colpeak to a magnitudeless than the voltage between said collector and base electrodes, and anoperating point of relatively high collector current will besubstantially instantaneously established.

38. A thermostatic device, comprising a body of P type semi-conductivematerial containing an inclusion of type semi-conductive materialpartially exposed on the external surface of said body, an emitterelectrode placed on the P type material near said inclusion, a collectorelectrode placed on said inclusion, a base electrode placed on said Ptype material and spaced from said emitter electrode, said collectorelectrode being initially adjusted in location and contact pressure suchthat no peak appears in the diode characteristic of saidcollector'electrode, means for biasing said emitter electrode positivewith respect to said base electrode, said emitter bias being so adjustedthat the peak which is caused, by said emitter bias, to appear in saidcollector characteristic has passed through a maximum and decreasesin'magnitude with increased emitter bias, means for biasing saidcollector electrode negatively to a predetermined magnitude with respectto said base electrode, said peak being only slightly greater inmagnitude than the voltage between said collector and base electrodes,to establish an operating point of relatively low collector current,whereby a small increase of ambient temperature will lower the voltageof riaeoaaae i i-21 '-said'='-peak a -mag-nitude -less than the 'mltagebetween said collector and base electrodes, and "an =-operating point ofrelatively high wollector current will 'be *substantially'iinstaritarie'ously es'tablished.

39. A thermostatic devioe, --comprisitig rra :body of N' -'typesemi'eoriductive -material containiii an --im?l11sion-of P itypesemi-conducti ve :mate- ..ra1 partially exposedon :the eXternalh'surfacef'of -said 'bodyfan emitter electro'd e:plaeedon the N 'type materialnear*saidinclusion; a colleotor electrodegplaced on said inc1usien,=a1base ielectrdde SIaeed Qmsaid -N type materialiandispaceditrom saidemitter :eleetro'd'e, said collector 'elec'tro'de "being initiallyadjusted in "location and contact pressure such that noweak appears -intlie diode characteristic of said collector e1ectrode,l:m'eans forbiasing I said -="emitter I electrode negative With respect to saidlease ele'ctrode; -said emitter b'ias being so adjusted that a peakappears 1 in Pisa-id zcollector *characteristic, means fon'biasirig'said mneemr -eleetrode positively -130 a rpredeterrrimed "magnitudewith respect t'o said base -'electrode, "said peak being only slightlygreate'r in magni- 'tiide 'thani-thevoltage betweensaid 'cc illecitorand Eb'ase electrodes, to 1 establish an :operating point orrelatively 10w "ccillector current, whereby a small -'-increase fambient temperature will lower the' voltageo'f said -p'eak to amagnitude: less' than the vdltage between the. collectoraridf baseelectrode, and an: operating -po'int -=of relativel y iiigh collector 1currei-it -Will be subs'taritia'lly sinsta'ntaneouslyestablished.

1 40; A relay dev-ice, comprisirig a bo'dy of -P" type asemi+conductivemater-ial containing an 5111- 'Iro'm said emitter ledtrode, means for:Ioiasing "said emitter elect-rode 'positive with respect to said'basel'ectrodepsaid ei-nitter bias being' so 'a'diusted tha'i-t -apea'k-appea-rs n -said collector-"characteristic, means ier biasingsaid-eollecternegatively "to "a pre'determine'd magnitude ivi'th respect "tosaid base electrode, -"s'aid=jpeak"beirig only slightly greater inmagnitude "than "the voltage *btween said collectorand"base eleotrodes,to-establish fan. "operating *point of "relatively low collector*current, whereby a small increase of ambient*'temperature '-wi-1llowerjthevoltage"of" said'peak to' "a "magnitude less tliair'the voltagebetweentsa'i'd col-lectorand base "electrodes, and an operating 'poi-n'ter relatively high collectorcurrerit *will' b'e 'sfibstantia-llyinstantaneously "established.

41. relay device, com-pri-s'in'gahody' of ""N? type semi-conductivematerial containing= an Linblus'ion "of P" type semi-conductive"material partially exposed ion theexternal" surface "of. said "bodyan'emitter electrode 'placed "on the ""N type "material'near "'sai'd*inclu-sion, "a collector electrode r'ilaced on -sai'd inc'lusion, '-abase electro'de ila'ce'd on said "'N 'type "material and 'spa'ced fromsaid emitter=*eleetrode,"thelocation -and eori'tactpressure'o'fsaid"collector electrode bei'n'g. initially so adjusted thatno peak-appears in its diode volteampere characteristic, a'n'd "meansfor -biasixig -=said emitter electrode negatively with'resp'e'ct tosai'd base e lectroiia'afload impeidance'incircuitfwith -saidfeolleetoreleetrode,

.22 *said remitter negative bias being "adjusted (such that thecollector characteristic peak .isISft-in-xax- 'imum magnitude, means.ior biasingsaid 001-.

lector ielectrod'e toz'sa :positive 'magnitude with respect tosaidbase-electrode"asuch that the load I lin'e wi-ll intersect *sai-d:collector characteristic rat a point just below saidmaximumpeakmagnitude to establish an 1 operating igpoint .iof arelatively ilow loadimpedancetcurrent, :wherebyaF-slight change in the :"emitter ele'ctrodecontact temperature fin either sense, :will ica'usessai'd ii'collecto'rcharacteristic -peak Ito be reduced :to a .magnitude such :th-a't' theload line will Lint-ersect'said :Tcollector charactieri'stic i-at onlyone 'lpoinlt, whereby an separating p'oi-n't ton relatively :high loadlimpedame currentisisubstantiallyinstantaneously= established.

2 42. A rrelay device, :c'cmprising 2a :body :of fP type semi-conductivematerial 'c'ontaining an aim- *clusion Iof f'N =f-type ssemi conductivematerial K partiallyi exposed on the external .surfa'ce of: said --body,an emitter electrode placed 'on the "P type ma'terialanear saidinclusion, a "collector electro'de placed "on rsaid. inclusion, -a "baseelec- ':trode iplaced :on :said i? 'type materi-al and -spaced from saidemitter electr0de,1the "location and c'ontact .pressure of saidcollector electrode -'beingf:initial1yiso adjuste'd'ithat nopeak-appears in its idiode volt-ampere characteristic, means for biasingsaid emitter electrode positively-with respect to saidibasaelectrode, aioad -impedance in circuit with said collectorelectrodepsaid emitterpositive bias -being adjusted such tha't the collector charact'eristicpeakis df'maximum mag- '-nitude, means for biasing-said collectorelectrode to a negative -magnitu'de 'w'it'h "respect to -=said "baseelectrode such that the load line will in- "tersect' saidcollectorcharacteristic at a "point just -be1o'w the. "maximum "peak qnagn'itu'de'to establish an operating =point-ef "relatively low -load impedancecu'rre'rit, whereby 1 a-s light change "in 'Lemitt'er electrode*con'ta'ct temperature in either sense, will cause said collectorr'i'haracteris'tic :peak to be reduced to a magnitude such that-the'lcad line wiil -iriterse'ct said collector characteristic a'tonly one-point, whereby an operating point of relatively high "load impedancecurren' t ,is substantially instantaneously estabilished.

43. -A relay device, "comprising -a -body of 'N type s'emiconductivematerial"containing an ill-r 'clusio'n o'f "fPf 'type 'serni conductive"material .par tia'lly exposed on :the external 'surf ace ar ears body,an emitter -electrode placed "on "the "N "type 'z-riaterial near saidinclusion, a colle'cztor electrode placed "on Said inclusion, a baseelectrode :placed on :said "N "type material 'and spaced from saidemitter electrode, said collector e'l'ectrode "being initially-adjustedin location and contact pressure such "that a peak appears in its diodevolt-ampere characteristic, -means for biasing-said collec'tor electrodepositively to a predeterminedmagnitude with 'respectto-'sai'd "baseelectrode, me'ansior biasin'g said emitter :ele'ctr ode positively with"respect *to said *base electrode. said emitter bi'asbein'g so adjustedthat the collectoripeak'is of ia magnitu'de such-that a l'oad line "willin'tersect said collector 'charac- Steris'tic atfa point justibelow saidpeak to establish an Ioperating anoint of relatively 210w *col- -lec'torcurrent, Whereby -a slight increasein-am- 'Jei'erit' temperatu-rewill'loWersaid peak to a magnitude su'ch that' =the loadline :willintersect said eollector characteristic at only one am, and anop'erating p'oint -'of relatively "high collector current willbe'$l-1llSi3aI115ia1ly instantaneously es- -tablished. r

44'. A relay device, comprising abody of P type semi-conductive materialcontaining an inclusion of N type semi-conductive material partiallyexposed on theexternal surface of said body, an emitter electrode placedon the P typeymaterial .near said inclusion, a collector for biasingsaid collector electrode negativelyto' apredetermined magnitude withrespect to said base electrode, means for biasing said emitter electrodenegatively with respect to said base electrode, said emitter bias beingso adjusted that thecollector peak is of a magnitude such that a loadline will intersect'the collector characteristic at a point just belowsaid peak to establish an operating point of relatively low collectorcurrent, whereby a slight rise in ambient temperature will lower saidpeak to a magnitude such that the loadline will intersect said collectorcharacteristic at only one point and an operating point of relativelyhigh collector current will be substantially instantaneouslyestablished,

45. A- relay device, comprising a body of "N? type semi-conductive-material containing, an

inclusion of- P type semi-conductive material partially exposed on theexternal surface of-said ,body, a collector electrode in contact withsaid inclusion, a base electrode placed on the N type material, saidcollector electrode being adjusted in location and contact pressure suchthat no peak appears-in the collector characteristic, an emitterelectrode in contact with N type material on said bodynear saidinclusion, means for positive magnitude with respect to said baseelectrode such that the load line will intersect said collectorcharacteristic at a point just below said maximum peak magnitude toestablish an operating point of relatively low load impedance current,whereby a slight change in either sense, in the voltage between theemitter electrode and the base electrode; will cause said collectorcharacteristic peak to be reduced to a magnitude such that the load linewill intersect said collector characteristic at only one point, wherebyan operating point of relatively high load impedance current issubstantially instantaneously established. v

46. A'relay device, comprising a body of P type semi-conductive materialcontaining aninclusion of N type semi-conductive material partiallyexposed on the. external surface of said body, a collectorelectrodeincontact with said inclusion, a base electrode placed on the Ptype .material, said collector electrode being adjusted in location andcontact pressure such that no peak appears in the collectorcharacteristic, an

emitter electrode in contact with P type masuch that the load line willintersect said'collector characteristicat only one point,.whereby anoperating point ofrelatively high load-impedance current issubstantially instantaneously established. 7 l U 47. A relay device,comprising a body of N type semi-conductive material containing aninclusion of P type semi-conductive material partially exposedon theexternal surface of said body, an emitter electrode placed .on the Ntype material near said inclusion, a collector electrode placed on saidinclusion, a-base electrode placed on said N type material andspacedifrom said emitter electrode, said collector electrode beinginitially adjusted in location and contact pressure such that a peakappears in its diode volt-ampere characteristic, means for biasing saidcollector electrode positively to a predetermined magnitude with respecttosaid base electrode, means for biasing said emitter electrodepositively with respect to said base electrode, said emitter bias beingso adjusted that the collector peak is of a clusion of N typesemi-conductive material partially exposed on the external surface ofsaid body, an emitter electrode placed on the P type material near saidinclusion, a collector electrode placed on said inclusion, saidcollector electrode being initially adjusted in location and contactpressure such that no peak appears in the diode characteristic of saidcollector electrode, a base electrode placed on said P type material andspaced from said emitter electrode, means for biasing said emitterelectrode positive with respect to said base electrode, said emitterbias being so adjusted that a peak appears in said collectorcharacteristic, means for biasingsaid collector negatively to apredetermined magnitude with respect to said base electrode, said peakbeing only slightly greater in magnitude than the voltage between saidcollector and base electrodes, to establish an operating. point ofrelatively low collector current, whereby a small decrease oftemperature in the vicinity of the emitter electrode will lower thevoltage of said peak to a magnitude less than the voltage between said 7collector and base electrodes, and an operating point of relatively highcollector current will be substantially instantaneously established.

49. A'relay device, comprising a body of P type semi-conductive materialcontaining an inclusion of N type semi-conductive material partiallyexposed on the external surface of said body, an emitter electrodeplaced on the P type material near said inclusion, a collector electrodeplaced on said inclusion, a base electrode placed on said P typematerial and spaced from said emitter electrode, said collectorelectrode being initially adjusted in location and contact pressure suchthat a peak appears in its diode voltampere characteristic, means forbiasing said collector electrode negatively to a predetermined magnitudewith respect to said base electrode, means for biasing said emitterelectrode negatively with respect to said base electrode, said emitterbias being so adjusted that the collector peak is of a magnitude suchthat a load line will intersect the collector characteristic at a pointjust below said peak to establish an operating point of relatively lowcollector current, whereby a slight rise in the temperature in thevicinity of the emitter electrode will lower said peak to a magnitudesuch that the load line will intersect said collector characteristic atonly one point and an operating point of relatively high collectorcurrent will be substantially instantaneously established.

50. A relay device, comprising a body of semiconductive material, a baseelectrode, a collector electrode, and an emitter electrode, in contactwith said body, a load impedance connected in F Number circuit with saidcollector electrode, means for applying biasing voltages to saidcollector and emitter electrodes, said biasing voltages being soadjusted that the collector characteristic intersects the load line 'atat least two points, and means for afiecting the emitter bias to causethe collector characteristic to intersect the load line at one pointonly, whereby the collector current instantaneously jumpsfrom onemagnitude to a substantially different magnitude.

51. A device as claimed in claim 50, wherein said means for affectingthe emitter bias com-' prises an input impedance connected in serieswith a source of emitter bias potential between the emitter and baseelectrode, and means for applying an input potential across said inputimpedance.

LLOYD P. HUNTER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Moore Nov. 21, 1950 Eberhard Dec. 5,1950 Lewis Dec. 26, 1950

